{"thcode":2,"term":{"code":2044,"name":"soil horizons","parent":1199,"scope":"Layers in soil defined by physical, chemical, biological, or mineralogical properties which vary with depth."},"uf":[{"name":"A horizon","usewith":false},{"name":"B horizon","usewith":false},{"name":"C horizon","usewith":false}],"bt":[{"code":1199,"name":"unconsolidated deposits","parent":1005,"scope":"Loosely bound sediments such as sand, gravel, and silt which tend to accumulate in low areas or valleys."},{"code":1005,"name":"rocks and deposits","parent":287,"scope":"Solid masses that make up the earth's crust as well as accumulations of materials. Use for major rock types and unconsolidated deposits. For deposits of economic value, see related terms."},{"code":287,"name":"earth characteristics","parent":1174,"scope":"The measurable, definable properties and features of the earth."},{"code":1174,"name":"topics","parent":1,"scope":"Themes, subjects, and concerns for which USGS information resources are relevant."},{"code":1,"name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[],"rt":[{"code":2268,"name":"biological soil crusts","parent":1080,"scope":"Communities commonly found on the soil surface in arid and semi-arid ecosystems, these consist of mosses, cyanobacteria, lichens, algae, and microfungi, which weave together and adhere to the soil to form a matrix that lessens erosion, supports nitrogen fixation, and retains moisture. These organisms are important to the functioning of ecosystems and to the organization of plant and soil communities."},{"code":1710,"name":"soil formation","parent":451,"scope":"Geological, geochemical, and ecological processes that work together to produce soils."},{"code":1081,"name":"soil sciences","parent":291,"scope":"Earth sciences dealing with the origin, classification, physical, chemical, and biological properties of soils."}]}